This was a great lesson in the opening for me. I suspect I was lost after 3.Q15.

6.i18 could be called a variation of the Medcalf defense. I do not see any decent alternative for white. Everything black does on the bottom is preparation for the block at i11.

|11.d15 would not have worked because of 12.j20.

|12.p19 is much stronger than |12.n18 because now my Q15 peg is rendered useless.

|19.m13 might have been better, but for example 20.n9 21.r9 22.n14 23.l11 24.l8 25.j12 26.j13